It recently occurred to me that there were quite a few home theater devices plugged in all the time at our home. I used a Kill-a-watt meter to measure the standby power usage of the devices, and came up with the following results.

Sub-wooferSitting Idle: 6.5 W (Watts) Playing Music: 9.5 W on average for pretty loud music

Chromecast AudioSitting Idle: 1.3 WStreaming Music: 1.4 W

CD PlayerSitting Idle: 5.5 W

ReceiverSitting Idle: 0.3 WOn - No Sound 40.0 W

Large Sony SpeakersSitting Idle: 9.0 WOn - No Sound 9.0 W

Record PlayerSitting Idle: 1.8 W

Of all the devices listed, we only use the Receiver, Chromecast Audio, and Sub-woofer. The Sony speakers need a line level input and I have not been able to get that out of the Receiver, so they're never turned on. Plus, the display on them has been long gone, so that doesn't help anything.

The switched surge protector itself consumes 1.4 W just sitting there.Using the Receiver as the switched port, the Sub-woofer and Chromecast Audio can be turned on with the receiver.This saves about 6.5 W, since the switched surge protector is a wash with the Chromecast.